Publications
| Title | Abstract | Year Filter | PMID(sorted ascending) Filter |
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| taxonomic identification, phenanthrene uptake activity, and membrane lipid alterations of the pah degrading arthrobacter sp. strain sphe3. | this report describes phenanthrene uptake as well as the effect of phenanthrene on the membrane phospholipid and fatty acid composition in a newly isolated bacterial strain, sphe3, that we taxonomically identified as arthrobacter sp. strain sphe3 is able to utilize phenanthrene as a carbon source at high rates and appears to internalize phenanthrene with two mechanisms: a passive diffusion when cells are grown on glucose, and an inducible active transport system when cells are grown on phenanthr ... | 2007 | 17583808 |
| cloning and characterization of the gene encoding endo-beta-1,3-glucanase from arthrobacter sp. nhb-10. | the glua gene, encoding an endo-beta-1,3-glucanase from arthrobacter sp. (strain nhb-10), was cloned and analyzed. the deduced endo-beta-1,3-glucanase amino acid sequence was 750 amino acids long and contained a 42 amino acid signal peptide with a mature protein of 708 amino acids. there was no similarity to known endo-beta-1,3-glucanases, but glua was partially similar to two fungal exo-beta-1,3-glucanases in glycoside hydrolase (gh) family 55. of five possible residues for catalysis and two mo ... | 2007 | 17587693 |
| stability of microbial communities in goat milk during a lactation year: molecular approaches. | the microbial communities in milks from one herd were evaluated during 1-year of lactation, using molecular methods to evaluate their stability and the effect of breeding conditions on their composition. the diversity of microbial communities was measured using two approaches: molecular identification by 16s and 18s rdna sequencing of isolates from counting media (two milks), and direct identification using 16s rdna from clone libraries (six milks). the stability of these communities was evaluat ... | 2007 | 17604934 |
| cultivable bacterial diversity of alkaline lonar lake, india. | aerobic, alkaliphilic bacteria were isolated and characterized from water and sediment samples collected in the winter season, january 2002 from alkaline lonar lake, india, having ph 10.5. the total number of microorganisms in the sediment and water samples was found to be 10(2)-10(6) cfu g(-1) and 10(2)-10(4) cfu ml(-1), respectively. one hundred and ninety-six strains were isolated using different enrichment media. to study the bacterial diversity of lonar lake and to select the bacterial stra ... | 2008 | 17604989 |
| synthesis of 4-hydroxyisoleucine by the aldolase-transaminase coupling reaction and basic characterization of the aldolase from arthrobacter simplex aku 626. | arthrobacter simplex aku 626 was found to synthesize 4-hydroxyisoleucine from acetaldehyde, alpha-ketobutyrate, and l-glutamate in the presence of escherichia coli harboring the branched chain amino acid transaminase gene (ilve) from e. coli k12 substrain mg1655. by using resting cells of a. simplex aku 626 and e. coli bl21(de3)/pet-15b-ilve, 3.2 mm 4-hydroxyisoleucine was produced from 250 mm acetaldehyde, 75 mm alpha-ketobutyrate, and 100 mm l-glutamate with a molar yield to alpha-ketobutyrate ... | 2007 | 17617727 |
| glycinebetaine accumulation is more effective in chloroplasts than in the cytosol for protecting transgenic tomato plants against abiotic stress. | tomato (lycopersicon esculentum mill. cv. moneymaker) plants were transformed with a gene for choline oxidase (coda) from arthrobacter globiformis. the gene product (coda) was targeted to the chloroplasts (chl-coda), cytosol (cyt-coda) or both compartments simultaneously (chlcyt-coda). these three transgenic plant types accumulated different amounts and proportions of glycinebetaine (gb) in their chloroplasts and cytosol. targeting coda to either the cytosol or both compartments simultaneously i ... | 2007 | 17617827 |
| the distribution of acetohydroxyacid synthase in soil bacteria. | most bacteria possess the enzyme acetohydroxyacid synthase, which is used to produce branched-chain amino acids. enteric bacteria contain several isozymes suited to different conditions, but the distribution of acetohydroxyacid synthase in soil bacteria is largely unknown. growth experiments confirmed that escherichia coli, salmonella enterica serotype typhimurium, and enterobacter aerogenes contain isozymes of acetohydroxyacid synthase, allowing the bacteria to grow in the presence of valine (w ... | 2008 | 17624809 |
| partial purification and chemical characterization of a glycoprotein (putative hydrocolloid) emulsifier produced by a marine bacterium antarctobacter. | during screening for novel emulsifiers and surfactants, a marine alphaproteobacterium, antarctobacter sp. tg22, was isolated and selected for its production of an extracellular emulsifying agent, ae22. this emulsifier was produced optimally in a low-nutrient seawater medium supplemented with glucose and was extractable by cold ethanol precipitation of the high-molecular-weight fraction (>100 kda). production of ae22 commenced towards the late exponential phase of growth, with maximum emulsifying ... | 2007 | 17641887 |
| biodegradation and bioremediation of endosulfan contaminated soil. | among the three mixed bacterial culture ae, be, and ce, developed by enrichment technique with endosulfan as sole carbon source, consortium ce was found to be the most efficient with 72% and 87% degradation of alpha-endosulfan and beta-endosulfan, respectively, in 20 days. in soil microcosm, consortium ae, be and ce degraded alpha-endosulfan by 57%, 88% and 91%, respectively, whereas beta-endosulfan was degraded by 4%, 60% and 67% after 30 days. ochrobacterum sp., arthrobacter sp., and burkholde ... | 2008 | 17646098 |
| [lignite microorganisms]. | the first demonstration that samples of lignite at a depth of 10 m are considerably enriched in bacteria is reported. according to direct microscopy, the abundance of bacteria was about 10(7) cells/g. about 70% of cells had intact cell membranes and small size, which points to their anabiotic state. the fungal mycelium length was no more than 1 m. lignite inoculation onto solid glucose-yeast-peptone medium allowed as to isolate bacteria of the genera bacillus, rhodococcus, arthrobacter, micrococ ... | 2007 | 17668464 |
| degradation of pentachlorophenol by pure and mixed cultures in two different soils. | pentachlorophenol (pcp) is the second highest volume pesticide used in the united states. it is a mutagenic compound whose exposure poses significant health effects, one of the most desirable, environmentally friendly treatment methods is bioremediation. for soil-based contamination, the effectiveness of bioremediation will also be affected by the presence of an active indigenous population, sorption of the contaminant onto the soil, and environmental parameters. | 2007 | 17668821 |
| complete degradation of butyl benzyl phthalate by a defined bacterial consortium: role of individual isolates in the assimilation pathway. | two bacterial strains, in consortium, were isolated by enrichment techniques from municipal waste-contaminated soil, which utilized butyl benzyl phthalate (bbp) as the sole carbon source. one of the isolates was identified as arthrobacter sp. strain wy and the other one as acinetobacter sp. strain fw based on the morphological, nutritional and biochemical characteristics and 16s rrna sequence analysis. various metabolites of bbp engendered by arthrobacter sp. strain wy were isolated and identifi ... | 2008 | 17669462 |
| [preparation of androsta-1,4-diene-3,17-dione from sterols using mycobacterium neoaurum vkpm as-1656 strain]. | a product of microbiological cleavage of the sterols side chain, androsta-1,4-diene-3,17-dione, is toxic for bacteria, in particular, actinobacteria of the genera mycobacterium and arthrobacter. sterols were transformed into androsta-1,4-diene-3,17-dione by culturing the m. neoaurum vkpm an-1656 strain in a high yield, provided that a sorbent was used for elimination of contact between the bacterial cells and the product. unlike the cholesterol side chain, the more branched chains of phytosterol ... | 2007 | 17682396 |
| continuous deodorization and bacterial community analysis of a biofilter treating nitrogen-containing gases from swine waste storage pits. | a biofilter inoculated with arthrobacter sp. was applied to the simultaneous elimination of trimethylamine (tma) and ammonia (nh3) from the exhaust air of swine waste storage pits. the results showed that the biofilter achieved average removal efficiencies of 96.8+/-2.5% and 97.2+/-2.3% for tma and nh3, respectively. a near-neutral ph (7.3-7.4) was maintained due to the accumulation of acid metabolites and the adsorption of alkaline nh3. low moisture demand, low pressure drop and high biofilm st ... | 2008 | 17697773 |
| production of volatile aroma compounds by bacterial strains isolated from different surface-ripened french cheeses. | twelve bacterial strains belonging to eight taxonomic groups: brevibacterium linens, microbacterium foliorum, arthrobacter arilaitensis, staphylococcus cohnii, staphylococcus equorum, brachybacterium sp., proteus vulgaris and psychrobacter sp., isolated from different surface-ripened french cheeses, were investigated for their abilities to generate volatile aroma compounds. out of 104 volatile compounds, 54 volatile compounds (identified using dynamic headspace technique coupled with gas chromat ... | 2007 | 17701035 |
| trapping of a dopaquinone intermediate in the tpq cofactor biogenesis in a copper-containing amine oxidase from arthrobacter globiformis. | the biogenesis of the topaquinone (tpq) cofactor of copper amine oxidase (cao) is self-catalyzed and requires copper and molecular oxygen. a dopaquinone intermediate has been proposed to undergo 1,4-addition of a copper-associated water molecule to form the reduced form of tpq (tpq(red)), followed by facile oxidation by o(2) to yield the mature tpq (tpq(ox)). in this study, we have incorporated a lysine residue in the active site of arthrobacter globiformis cao (agao) by site-directed mutagenesi ... | 2007 | 17715921 |
| cloning of a gene cluster involved in the catabolism of p-nitrophenol by arthrobacter sp. strain js443 and characterization of the p-nitrophenol monooxygenase. | the npd gene cluster, which encodes the enzymes of a p-nitrophenol catabolic pathway from arthrobacter sp. strain js443, was cloned and sequenced. three genes, npdb, npda1, and npda2, were independently expressed in escherichia coli in order to confirm the identities of their gene products. npda2 is a p-nitrophenol monooxygenase belonging to the two-component flavin-diffusible monooxygenase family of reduced flavin-dependent monooxygenases. npda1 is an nadh-dependent flavin reductase, and npdb i ... | 2007 | 17720792 |
| cloning and characterization of a 4-hydroxyphenylacetate 3-hydroxylase from the thermophile geobacillus sp. pa-9. | a 4-hydroxyphenylacetic acid (4-hpa) hydroxylase-encoding gene, on a 2.7-kb genomic dna fragment, was cloned from the thermophile geobacillus sp. pa-9. the geobacillus sp. pa-9 4-hpa hydroxylase gene, designated hpah, encodes a protein of 494 amino acids with a predicted molecular mass of 56.269 da. the deduced amino-acid sequence of the hpah gene product displayed <30% amino-acid sequence identity with the larger monooxygenase components of the previously characterized two-component 4-hpa 3-hyd ... | 2007 | 17805928 |
| 6-aminohexanoate oligomer hydrolases from the alkalophilic bacteria agromyces sp. strain ky5r and kocuria sp. strain ky2. | alkalophilic, nylon oligomer-degrading strains, agromyces sp. and kocuria sp., were isolated from the wastewater of a nylon-6 factory and from activated sludge from a sewage disposal plant. the 6-aminohexanoate oligomer hydrolases (nylc) from the alkalophilic strains had 95.8 to 98.6% similarity to the enzyme in neutrophilic arthrobacter sp. but had superior thermostability, activity under alkaline conditions, and affinity for nylon-related substrates, which would be advantageous for biotechnolo ... | 2007 | 17827307 |
| biodegradative potential and characterization of psychrotolerant polychlorinated biphenyl-degrading marine bacteria isolated from a coastal station in the terra nova bay (ross sea, antarctica). | antarctic marine bacteria were screened for their ability to degrade polychlorinated biphenyls (pcb) as the sole carbon and energy source at both 4 degrees c and 15 degrees c. pcb-degrading isolates (7.1%) were identified by sequencing their 16s rdna as pseudoalteromonas, psychrobacter and arthrobacter members. one representative isolate per genera was selected for evaluating the biodegradative potential under laboratory scale and phenotypically characterized. removal of individual pcb congeners ... | 2007 | 17854841 |
| enzymatic synthesis of cephalosporins. the immobilized acylase from arthrobacter viscosus: a new useful biocatalyst. | the acylase from arthrobacter viscosus was immobilized, studied in the enzymatic synthesis of some cephalosporins by kinetically controlled n-acylation (kcna) of different cephem nuclei, and compared with the penicillin g acylase (pga) from escherichia coli. the reaction outcomes were dependent on the acylase microbial source and on the type of immobilization support. generally, both enzymes, when immobilized onto hydrophilic resins such as glyoxyl-agarose (activated with aldehyde groups), displ ... | 2007 | 17879093 |
| trans-stilbene degradation by arthrobacter sp. sl3 cells. | trans-stilbene degradation was examined by the reaction using resting cells of microorganisms isolated through the enrichment culture using trans-stilbene. the strain sl3, showing the highest trans-stilbene-degrading activity, was identified as arthrobacter sp. one of the reaction products was identified to be cis,cis-muconic acid. arthrobacter sp. sl3 cells also transformed benzaldehyde, benzoic acid and catechol into cis,cis-muconic acid, suggesting that one benzene ring of trans-stilbene was ... | 2008 | 17885812 |
| identification of bacteria from clinical samples using bartonella alpha-proteobacteria growth medium. | in an effort to overcome historical problems associated with the isolation of bartonella species from animal and human blood samples, our laboratory developed a novel, chemically modified, insect-based, liquid culture medium (bartonella alpha-proteobacteria growth medium, bapgm). in this study, we describe the isolation of non-bartonella bacteria from aseptically obtained human blood and tissue samples that were inoculated into bapgm pre-enrichment culture medium, and were obtained during attemp ... | 2007 | 17889384 |
| phylogenetic diversity of bacteria isolates from the qinghai-tibet plateau permafrost region. | the qinghai-tibet plateau in east asia is a unique and important permafrost environment. however, its microbiology remains largely unexplored to date. in this study, sediment samples were collected from the qinghai-tibet plateau permafrost region, bacteria isolation procedures were performed 8 times, and the samples incubated at 4 degrees c for nearly 3 months. the number of colony forming units (cfu) ranged from 0 to 10(7)/(g dry soil). the quantity of culturable bacteria grew exponentially wit ... | 2007 | 17898857 |
| arbuscular mycorrhizal fungi and rhizospheric bacteria diversity along an altitudinal gradient in south american puna grassland. | rhizospheric soil samples were taken from puna native grasses along an altitudinal gradient. biodiversity of arbuscular mycorrhizal fungi (amf) and associated bacteria was analyzed considering altitude and grasses photosynthetic pathways (metabolic type c3, c4). cultivation-dependent approaches were applied to obtain further information about the phylogeny of the dominating cultivable aerobic-heterotrophic bacteria communities present in rhizospheric soil samples. in average, the bacterial count ... | 2008 | 17912580 |
| degradation of mixtures of phenolic compounds by arthrobacter chlorophenolicus a6. | in this study the chlorophenol-degrading actinobacterium, arthrobacter chlorophenolicus a6, was tested for its ability to grow on mixtures of phenolic compounds. during the experiments depletion of the compounds was monitored, as were cell growth and activity. activity assays were based on bioluminescence output from a luciferase-tagged strain. when the cells were grown on a mixture of 4-chlorophenol, 4-nitrophenol and phenol, 4-chlorophenol degradation apparently was delayed until 4-nitrophenol ... | 2008 | 17917705 |
| viability, diversity and composition of the bacterial community in a high arctic permafrost soil from spitsbergen, northern norway. | the viable and non-viable fractions of the bacterial community in a 2347-year-old permafrost soil from spitsbergen were subjected to a comprehensive investigation using culture-independent and culture-dependent methods. live/dead baclight staining revealed that 26% of the total number of bacterial cells were viable. quantitatively, aerobic microcolonies, aerobic colony-forming units and culturable anaerobic bacteria comprised a minor fraction of the total number of viable bacteria, which underli ... | 2007 | 17922769 |
| enhancement of androstadienedione production from progesterone by biotransformation using the hydroxypropyl-beta-cyclodextrin complexation technique. | the enhanced production of androstadienedione (add) from progesterone (p) using the hydroxypropyl-beta-cyclodextrin (hpbetacd) complexation technique by biotransformation was demonstrated. the microorganisms used were bacillus sphaericus atcc 245, b. sphaericus atcc 7063, b. sphaericus atcc 13805, arthrobacter simplex atcc 6946, b. sphaericus tistr 670 and those screened from soils in chiang mai province, thailand which were b. sphaericus srp i, b. sphaericus srp ii and b. sphaericus srp iii. th ... | 2008 | 17936614 |
| [phylogenetic diversity of culturable bacteria in the ancient salt deposits of the yipinglang salt mine, p. r. china]. | the microbial diversity of cultivable bacteria, isolated from the ancient salt deposits from the yipinglang salt mine (ypl) in the yunnan province, p. r. china,was investigated by using conventional culture-dependent method and phylogenetic analyses based on 16s rrna gene sequence comparisons. 38 bacteria strains were isolated from the brine, halite and saline soil samples on mba (marine broth agar 2216, difco) and isp 2 (international streotomyces project medium 2) media supplemented with 0.5-3 ... | 2007 | 17944352 |
| oligosaccharide profiles of the prostate specific antigen in free and complexed forms from the prostate cancer patient serum and in seminal plasma: a glycopeptide approach. | the oligosaccharide structures of prostate specific antigen (psa) are expected to be useful in discriminating prostate cancer from benign conditions both accompanied by increased serum psa levels. a large proportion of psa forms a covalent complex with a glycoprotein, alpha(1)-antichymotrypsin, in human blood. in the present study, the glycan profiles of free and complexed forms of psa from cancer patient serum and of seminal plasma psa were compared by analyzing the glycopeptides obtained by ly ... | 2008 | 17956937 |
| d-serine dehydratase from chicken kidney: a vertebral homologue of the cryptic enzyme from burkholderia cepacia. | d-serine dehydratase (dsd) catalyses the conversion of d-serine to pyruvate and ammonia. d-serine is a physiological modulator of glutamate neurotransmission in vertebrate brains. in mammals d-serine is degraded by d-amino-acid oxidase, whereas in chicken brain it is degraded by dsd, as we have recently demonstrated [tanaka et al. (2007) anal. biochem. 362, 83-88]. to clarify the roles of dsd in avian species, we purified dsd from chicken kidney. the purified enzyme was a heterodimer consisting ... | 2008 | 17977854 |
| microbial interactions within a cheese microbial community. | the interactions that occur during the ripening of smear cheeses are not well understood. yeast-yeast interactions and yeast-bacterium interactions were investigated within a microbial community composed of three yeasts and six bacteria found in cheese. the growth dynamics of this community was precisely described during the ripening of a model cheese, and the lotka-volterra model was used to evaluate species interactions. subsequently, the effects on ecosystem functioning of yeast omissions in ... | 2008 | 17981942 |
| [changes in viability of two antarctic marine bacteria exposed to solar radiation in the water column: influence of vertical mixing]. | the effect of uv radiation on two antarctic marine bacterial strains (uvps and uvvi) was studied in the water column of potter cove (south shetland, antarctica). quartz flasks were filled with the bacterial suspensions and exposed to solar radiation at 0 m, 1 m and 3 m depth. assays using flasks exposed to direct solar radiation and others using flasks covered with/by interferential filters which discriminate between uva and uvb, were performed. in other assays, a vertical mixing of 4 m/h was si ... | 2007 | 17987855 |
| short-term effects of amoxicillin on bacterial communities in manured soil. | antibiotic-resistant bacteria, nutrients and antibiotics that enter the soil by means of manure may enhance the proportion of bacteria displaying antibiotic resistance among soil bacteria and may affect bacterial community structure and function. to investigate the effect of manure and amoxicillin added to manure on soil bacterial communities, microcosm experiments were performed with two soil types and the following treatments: (1) nontreated, (2) manure-treated, (3) treated with manure supplem ... | 2007 | 17991020 |
| isolation and assessment of phytate-hydrolysing bacteria from the delmarva peninsula. | the delaware-maryland-virginia (delmarva) peninsula, flanking one side of the chesapeake bay, is home to a substantial broiler chicken industry. as such, it produces a significant amount of manure that is typically composted and spread onto local croplands as a fertilizer. phytate (myo inositol hexakisphosphate), the major form of organic phosphorus in the manure, can be hydrolysed by microorganisms to produce orthophosphate. orthophosphate is a eutrophication agent which can lead to algal bloom ... | 2007 | 17991037 |
| aerobic uranium (vi) bioprecipitation by metal-resistant bacteria isolated from radionuclide- and metal-contaminated subsurface soils. | in this study, the immobilization of toxic uranium [u(vi)] mediated by the intrinsic phosphatase activities of naturally occurring bacteria isolated from contaminated subsurface soils was examined. the phosphatase phenotypes of strains belonging to the genera, arthrobacter, bacillus and rahnella, previously isolated from subsurface soils at the us department of energy's (doe) oak ridge field research center (orfrc), were determined. the orfrc represents a unique, extreme environment consisting o ... | 2007 | 17991039 |
| bacterial endophytes contribute to abiotic stress adaptation in pepper plants (capsicum annuum l.). | endophytes are nonpathogenic plant-associated bacteria that can play an important role in plant vitality and may confer resistance to abiotic or biotic stress. the effects of 5 endophytic bacterial strains isolated from pepper plants showing 1-aminocyclopropane-1-carboxylate deaminase activity were studied in sweet pepper under in vitro conditions. four of the strains tested showed production of indole acetic acid. plant growth, osmotic potential, free proline content, and gene expression were m ... | 2007 | 18026213 |
| simultaneous mineralization of glyphosate and diuron by a consortium of three bacteria as free- and/or immobilized-cells formulations. | a bacterial consortium able to mineralize two herbicides, glyphosate (pseudomonas 4asw) and diuron (arthrobacter sp. n4 and delftia acidovorans), was cultivated in both a synthetic culture medium without phosphate and a sediment extract medium. in the aim at optimizing glyphosate and diuron mineralization, all the combinations, i.e., free and/or immobilized cells in ca-alginate beads were tested. with the synthetic medium, the simultaneous mineralization of glyphosate and diuron required at leas ... | 2008 | 18026726 |
| biphenyl-utilizing bacteria and their functional genes in a pine root zone contaminated with polychlorinated biphenyls (pcbs). | bacteria and functional genes associated with biphenyl (bp) degradation in the root zone of an austrian pine (pinus nigra l.) growing naturally in polychlorinated-bp (pcb)-contaminated soil were identified using stable isotope probing (sip) integrated with comprehensive functional gene analyses. sip revealed 75 different genera that derived carbon from 13c-bp, with pseudonocardia, kribella, nocardiodes and sphingomonas predominating carbon acquisition. rhodococcus spp. were not detected with sip ... | 2007 | 18043623 |
| microbial community profiling in cis- and trans-dichloroethene enrichment systems using denaturing gradient gel electrophoresis. | the effective and accurate assessment of the total microbial community diversity is one of the primary challenges in modem microbial ecology, especially for the detection and characterization of unculturable populations and populations with a low abundance. accordingly, this study was undertaken to investigate the diversity of the microbial community during the biodegradation of cis- and trans-dichloroethenes in soil and wastewater enrichment cultures. community profiling using pcr targeting the ... | 2007 | 18051265 |
| cloning, expression, and characterization of bacillus sp. snu-7 inulin fructotransferase. | a gene encoding inulin fructotransferase (di-d-fructofuranose 1,2': 2,3' dianhydride [dfa iii]-producing iftase, ec 4.2.2.18) from bacillus sp. snu-7 was cloned. this gene was composed of a single, 1,353-bp open reading frame encoding a protein composed of a 40-amino acid signal peptide and a 410-amino acid mature protein. the deduced amino acid sequence was 98% identical to arthrobacter globiformis c11-1 iftase (dfa iii-producing). the enzyme was successfully expressed in e. coli as a functiona ... | 2007 | 18051351 |
| two bacterial entophytes eliciting both plant growth promotion and plant defense on pepper (capsicum annuum l.). | plant growth-promoting rhizobacteria (pgpr) have the potential to be used as microbial inoculants to reduce disease incidence and severity and to increase crop yield. some of the pgpr have been reported to be able to enter plant tissues and establish endophytic populations. here, we demonstrated an approach to screen bacterial endophytes that have the capacity to promote the growth of pepper seedlings and protect pepper plants against a bacterial pathogen. initially, out of 150 bacterial isolate ... | 2007 | 18051359 |
| [study on the atrazine-degrading genes in arthrobacter sp. ag1]. | atrazine could be used as the sole carbon, nitrogen and energy sources for growth by strain arthrobacter sp. ag1, and the atrazine-degrading genes of ag1 were found to be the combination of trzn, atzb and atzc. the atrazine chloride hydrolysase gene trzn was cloned by pcr amplification,whose sequence shared 99% identity with that of norcardioides sp. c190. two large plasmids were found in ag1,and trzn and atzb were confirmed to be localized on the larger plasmid pag1 by the method of southern hy ... | 2007 | 18051853 |
| [screening and function analysis of a cyclohexanone-degrading bacterium cn1 from deep sea sediment]. | micrococcu luteus cn1 was found to be able to utilize cyclohexanone well from the strains originally isolated from pacific ocean sediment. the optimum conditions for its growth were determined as 25 degrees c -37 degrees c, ph 8, salinity 6%. it could survive in the medium with high concentration of cyclohexanone ( > 44% v/v), and grew most vigorously in medium with 16.7% (v/v) cyclohexanone. cn1 could transform cyclohexanol to cyclohexanone which could be further degraded and mineralized quickl ... | 2007 | 18062257 |
| chromate reduction by arthrobacter cr47 in biofilm packed bed reactors. | bacterial strain cr47 was isolated from a landfarming process soil sample. it was identified, by 16s rdna sequencing, as arthrobacter sp. the time course of the cr(vi) reduction was monitored in batch operated packed bed biofilm reactors (12 ml void volume) and in recirculating packed bed biofilm reactors (100 ml void volume) inoculated with bacterial strain cr47. the reduction was evaluated with, 30 mg l(-1) cr(vi) laboratory solutions prepared with k2cr2o7 and enriched with glucose-minimal med ... | 2008 | 18063473 |
| two closely related pathways of nicotine catabolism in arthrobacter nicotinovorans and nocardioides sp. strain js614. | a virtually identical nicotine catabolic pathway including the heterotrimeric molybdenum enzyme nicotine and 6-hydroxy-pseudo-oxynicotine dehydrogenase, 6-hydroxy-l: -nicotine oxidase, 2,6-dihydroxy-pseudo-oxynicotine hydrolase, and 2,6-dihydroxypyridine hydroxylase have been identified in a. nicotinovorans and nocardioides sp. js614. enzymes catalyzing the same reactions and similar protein antigens were detected in the extracts of the two microorganisms. nicotine blue and methylamine, two end ... | 2008 | 18071673 |
| effect of immobilization on kinetic and thermodynamic characteristics of sulfide oxidase from arthrobacter species. | in order to determine the impact of immobilization on biocatalytic efficacy of sulfide oxidase, the kinetic and thermodynamic properties of native and deae-cellulose immobilized sulfide oxidase from arthrobacter species fr-3 were evaluated. immobilization increased the catalytic efficiency of sulfide oxidase by producing a lower michaelis-menten constant (km) and a higher rate of catalysis (vmax) at different temperatures. the first-order kinetic analysis of thermal denaturation demonstrated tha ... | 2008 | 18080911 |
| effect of shadowing on survival of bacteria under conditions simulating the martian atmosphere and uv radiation. | spacecraft-associated spores and four non-spore-forming bacterial isolates were prepared in atacama desert soil suspensions and tested both in solution and in a desiccated state to elucidate the shadowing effect of soil particulates on bacterial survival under simulated martian atmospheric and uv irradiation conditions. all non-spore-forming cells that were prepared in nutrient-depleted, 0.2-microm-filtered desert soil (dse) microcosms and desiccated for 75 days on aluminum died, whereas cells p ... | 2008 | 18083857 |
| facultative but persistent trans-generational immunity via the mother's eggs in bumblebees. | it is widely acknowledged that a mother, and the maternal environment, can have a profound effect on the phenotype of her offspring. for example, immunocompetent vertebrate mothers can pass on immune factors to their otherwise immune naïve offspring. recently, it has also been demonstrated in invertebrates that maternal contact with pathogens and immune elicitors can have a positive impact on offspring resistance and immune system components. here, using a cross-fostering design, we show that tr ... | 2007 | 18088585 |
| arthrobacter subterraneus sp. nov., isolated from deep subsurface water of the south coast of korea. | strain ch7t, a pale yellow-pigmented bacterium and new isolate from deep subsurface water of the south coast of korea, was subjected to a polyphasic taxonomic study. ch7t grew between 5 and 37 degrees c, ph 5.3-10.5, and tolerated up to 13% nacl. a phylogenetic analysis based on 16s rrna gene sequences showed that strain ch7t was associated with the genus arthrobacter and phylogenetically closely related to the type strains arthrobacter tumbae (99.4%) and arthrobacter parietis (99.1%). however, ... | 2007 | 18092474 |
| [a case of catheter-related bacteremia by arthrobacter woluwensis.]. | arthrobacter woluwensis, a catalase-positive coryneform bacterium recognized as an opportunistic pathogen, was repeatedly isolated from the blood of a 56-year-old male patient with metastatic colon cancer. the isolate was identified by various phenotypic tests and by sequencing analysis of 16s rrna. antimicrobial susceptibility testing was performed by e-test; the mics to vancomcyin, cefotamine, and penicillin were 1.5 microg/ml, >64 microg/ml, and 4 microg/ml, respectively. the patient was trea ... | 2006 | 18156709 |
| [effect of quinocitrinines from the fungus penicillium citrinum on the respiration of yeasts and bacteria]. | we studied the effect of quinocitrinines on the respiratory activity of yeasts (yarrowia lipolytica) and bacteria (arthrobacter globiformis). quinocitrinines were shown to activate respiration of native cells in both types of organisms. studies of yeast mitochondria showed that quinocitrinine exerts an uncoupling effect on oxidative phosphorylation, which activates the respiration, reduces the respiratory control, and decreases the adp/o ratio. experiments with intact mitochondria and native cel ... | 2007 | 18173114 |
| arthrobacter oryzae sp. nov. and arthrobacter humicola sp. nov. | two novel bacterial strains were isolated from a paddy soil sample collected in japan using gpm agar plates supplemented with superoxide dismutase and/or catalase. the strains were gram-positive, catalase-positive and motile, with lysine as the peptidoglycan diagnostic diamino acid and acetyl as the peptidoglycan acyl type. the major menaquinone was mk-9(h(2)). mycolic acids were not detected. the g+c content of the dna was 66-68 mol%. on the basis of phenotypic analysis, 16s rrna gene sequence ... | 2008 | 18175682 |
| degradation of 4-fluorophenol by arthrobacter sp. strain if1. | a gram-positive bacterial strain capable of aerobic biodegradation of 4-fluorophenol (4-fp) as the sole source of carbon and energy was isolated by selective enrichment from soil samples collected near an industrial site. the organism, designated strain if1, was identified as a member of the genus arthrobacter on the basis of 16s ribosomal rna gene sequence analysis. arthrobacter strain if1 was able to mineralize 4-fp up to concentrations of 5 mm in batch culture. stoichiometric release of fluor ... | 2008 | 18228015 |
| comparative analysis of eight arthrobacter plasmids. | despite the prevalence of arthrobacter in the environment little is known about their plasmids, or the capacity of arthrobacter plasmids to mediate horizontal gene transfer. in this study, we compared eight plasmids from five arthrobacter strains in order to identify putative core maintenance genes for replication, segregation, and conjugation. iteron like sequences were identified on some of the plasmids; however, no genes with obvious similarity to known replication sequences such as an origin ... | 2008 | 18241920 |
| the effect of cysteine on production of volatile sulphur compounds by cheese-ripening bacteria. | the effect of cysteine on the ability of smear cheese-ripening bacteria (brevibacterium linens and arthrobacter spp) to produce volatile sulphur compounds (vsc) from methionine was studied. these bacteria were cultivated in a synthetic medium supplemented with various cysteine concentrations with or without methionine. cultures with only cysteine showed slightly lower levels of vsc produced and an unpleasant odour like rotten eggs, resulting from hydrogen sulphide production. the levels and prof ... | 2008 | 18262300 |
| novel chromium tolerant microorganisms: isolation, characterization and their biosorption capacity. | effluent from tannery, electroplating and electronic industries contain chromium which is highly toxic. this paper reports isolation of chromium tolerant microorganisms from solid waste as well as liquid effluent of an electroplating industry. nine isolates were obtained that can tolerate chromium concentration up to 700mg/l. they reach their stationary phase within 8-12h and can biosorb 95% of initial 200mg/l concentration of chromium within 4-10h. fourier transform infra red analysis of the bi ... | 2008 | 18272220 |
| commercial ripening starter microorganisms inoculated into cheese milk do not successfully establish themselves in the resident microbial ripening consortia of a south german red smear cheese. | production of smear-ripened cheese critically depends on the surface growth of multispecies microbial consortia comprising bacteria and yeasts. these microorganisms often originate from the cheese-making facility and, over many years, have developed into rather stable, dairy-specific associations. while commercial smear starters are frequently used, it is unclear to what degree these are able to establish successfully within the resident microbial consortia. thus, the fate of the smear starters ... | 2008 | 18281427 |
| [isolation and degrading characters of chlorpyrifos degrading bacteria xz-3]. | a strain of bacterium xz-3 capable of highly degrading chlorpyrifos was screened from the soil sample collected from a pesticide plant after taming and enrichment. based on analysis of phenotype, physiological and biochemical characters and 16s rdna, xz-3 was identified as arthrobacter sp.. the effects of carbon source, ph, temperature and chlorpyrifos concentration on degradation were determined. the growth of bacteria in culture media were measured by visible absorption spectrophotometry under ... | 2007 | 18290445 |
| rapid mineralization of the phenylurea herbicide diuron by variovorax sp. strain srs16 in pure culture and within a two-member consortium. | the phenylurea herbicide diuron [n-(3,4-dichlorophenyl)-n,n-dimethylurea] is widely used in a broad range of herbicide formulations, and consequently, it is frequently detected as a major water contaminant in areas where there is extensive use. we constructed a linuron [n-(3,4-dichlorophenyl)-n-methoxy-n-methylurea]- and diuron-mineralizing two-member consortium by combining the cooperative degradation capacities of the diuron-degrading organism arthrobacter globiformis strain d47 and the linuro ... | 2008 | 18296530 |
| synthesis and inhibitory activity of oligosaccharide thiazolines as a class of mechanism-based inhibitors for endo-beta-n-acetylglucosaminidases. | a facile synthesis of oligosaccharide-thiazoline derivatives of n-glycans as a novel class of inhibitors for endo-beta-n-acetylglucosaminidases was described. it was found that the external sugar residues on the n-glycan core could enhance the inhibitory potency. while the manbeta1,4glcnac- and man3glcnac-thiazolines were only moderate inhibitors, the large man9glcnac-thiazoline demonstrated potent inhibitory activity, with an ic(50) of 0.22 and 0.42 microm against the arthrobacter enzyme (endo- ... | 2008 | 18304822 |
| application of pcr-sscp for molecular epidemiological studies on the exposure of farm children to bacteria in environmental dust. | the environmental exposure of farm children to microorganisms in dust has become a focus of interest, since microbial exposure on farms has been related to a reduced prevalence of asthma and atopic diseases in children. previous studies almost exclusively focused on the determination of microbial counts using conventional culturing or the determination of microbial compounds i.e. endotoxins. in this study pcr-sscp (single-strand conformation polymorphism) was modified for characterising bacteria ... | 2008 | 18321601 |
| biofiltration of trimethylamine, dimethylamine, and methylamine by immobilized paracoccus sp. cp2 and arthrobacter sp. cp1. | a biofilter using granular activated carbon with immobilized paracoccus sp. cp2 was applied to the elimination of 10-250 ppm of trimethylamine (tma), dimethylamine (dma), and methylamine (ma). the results indicated that the system effectively treated ma (>93%), dma (>90%), and tma (>85%) under high loading conditions, and the maximum degradation rates were 1.4, 1.2, and 0.9g-nkg(-1) gac d(-1). among the three different amines treated, tma was the most difficult to degrade and resulted in ammonia ... | 2008 | 18331754 |
| characterization of a cryptic plasmid from a greenland ice core arthrobacter isolate and construction of a shuttle vector that replicates in psychrophilic high g+c gram-positive recipients. | over 60 greenland glacial isolates were screened for plasmids and antibiotic resistance/sensitivity as the first step in establishing a genetic system. sequence analysis of a small, cryptic, 1,950 bp plasmid, p54, from isolate gic54, related to arthrobacter agilis, showed a region similar to that found in theta replicating rhodococcus plasmids. a 6,002 bp shuttle vector, psvj21, was constructed by ligating p54 and puc18 and inserting a chloramphenicol acetyl transferase (cat) cassette conferring ... | 2008 | 18335166 |
| arthrobacter soli sp. nov., a novel bacterium isolated from wastewater reservoir sediment. | a novel gram-positive bacterium, designated syb2t, was isolated from wastewater reservoir sediment, and a polyphasic taxonomic study was conducted based on its morphological, physiological, and biochemical features, as well as the analysis of its 16s rrna gene sequence. during the phylogenetic analysis of the strain syb2t, results of a 16s rrna gene sequence analysis placed this bacterium in the genus arthrobacter within the family micrococcaceae. syb2t and arthrobacter protophormiae atcc 19271t ... | 2008 | 18337691 |
| functional diversity and electron donor dependence of microbial populations capable of u(vi) reduction in radionuclide-contaminated subsurface sediments. | in order to elucidate the potential mechanisms of u(vi) reduction for the optimization of bioremediation strategies, the structure-function relationships of microbial communities were investigated in microcosms of subsurface materials cocontaminated with radionuclides and nitrate. a polyphasic approach was used to assess the functional diversity of microbial populations likely to catalyze electron flow under conditions proposed for in situ uranium bioremediation. the addition of ethanol and gluc ... | 2008 | 18378664 |
| chemostat selection of a bacterial community able to degrade s-triazinic compounds: continuous simazine biodegradation in a multi-stage packed bed biofilm reactor. | using a successive transfer method on mineral salt medium containing simazine, a microbial community enriched with microorganisms able to grow on simazine was obtained. afterwards, using a continuous enrichment culture procedure, a bacterial community able to degrade simazine from an herbicide formulation was isolated from a chemostat. the continuous selector, fed with a mineral salt medium containing simazine and adjuvants present in the commercial herbicide formulation, was maintained in opera ... | 2008 | 18392868 |
| catalytic mechanism of inulinase from arthrobacter sp. s37. | detailed catalytic roles of the conserved glu323, asp460, and glu519 of arthrobacter sp. s37 inulinase (enia), a member of the glycoside hydrolase family 32, were investigated by site-directed mutagenesis and ph-dependence studies of the enzyme efficiency and homology modeling were carried out for enia and for d460e mutant. the enzyme efficiency (k(cat)/k(m)) of the e323a and e519a mutants was significantly lower than that of the wild-type due to a substantial decrease in k(cat), but not due to ... | 2008 | 18395004 |
| [isolation of antibiotic resistance bacterial strains from east siberia permafrost sediments]. | a collection of bacterial antibiotic resistance strains isolated from arctic permafrost subsoil sediments of various age and genesis was created. the collection included approximately 100 strains of gram-positive (firmicutes, arthrobacter) and gram-negative bacteria (bacteroidetes, gamma-proteobacteria, and alpha-proteobacteria) resistant to aminoglycoside antibiotics (gentamycin, kanamycin, and streptomycin), chloramphenicol and tetracycline. antibiotic resistance spectra were shown to differ i ... | 2008 | 18409385 |
| genetic analysis of phenylacetic acid catabolism in arthrobacter oxydans cect386. | arthrobacter oxydans cect386 is a gram-positive bacterium able to use either phenylacetic acid or phenylacetaldehyde as the sole carbon and energy source for aerobic growth. genes responsible for the catabolism of these compounds have been located at two chromosomal regions and were organized in one isolated paan gene and two putative paa operons, one consisting of the paad, paaf, tetr and prot genes, and one consisting of the paag, paah, paai, paaj, paak and paab genes. the identity of the paaf ... | 2008 | 18437357 |
| structure of 2,6-dihydroxypyridine 3-hydroxylase from a nicotine-degrading pathway. | the enzyme 2,6-dihydroxypyridine-3-hydroxylase catalyzes the sixth step of the nicotine degradation pathway in arthrobacter nicotinovorans. the enzyme was produced in escherichia coli, purified and crystallized. the crystal structure was solved at 2.6 a resolution, revealing a significant structural relationship with the family of fad-dependent aromatic hydroxylases, but essentially no sequence homology. the structure was aligned with those of the established family members, showing that the fad ... | 2008 | 18440023 |
| study of cadmium, zinc and lead biosorption by orange wastes using the subsequent addition method. | the biosorption of several metals (cd2+, zn2+ and pb2+) by orange wastes has been investigated in binary systems. multicomponent sorption isotherms were obtained using an original procedure, similar to that proposed by pagnanelli et al. [pagnanelli, f., petrangeli, m.p., toro, l., trifoni, m., veglio, f., 2001a. biosorption of metal ions on arthrobacter sp.: biomass characterization and biosorption modelling. environ. sci. technol. 34, 2773-2778] for monoelement systems, known as subsequent addi ... | 2008 | 18440805 |
| [restriction endonuclease asi256i recognizing the nucleotide sequence 5'-gatc-3']. | a strain producing a restriction endonuclease was isolated from soil samples and identified as the arthrobacter sp. strain ck256. the enzyme produced by this strain was termed asi2561. the isolation procedure for this enzyme was described, and the optimal conditions for its function were determined. it was shown that the restriction endonuclease asi256i is a true isoschizomer of mboi, it has a temperature optimum of 6 degrees c, and can be used in molecular-biological and genetic-engineering stu ... | 2008 | 18491594 |
| swapping metals in fe- and mn-dependent dioxygenases: evidence for oxygen activation without a change in metal redox state. | biological o(2) activation often occurs after binding to a reduced metal [e.g., m(ii)] in an enzyme active site. subsequent m(ii)-to-o(2) electron transfer results in a reactive m(iii)-superoxo species. for the extradiol aromatic ring-cleaving dioxygenases, we have proposed a different model where an electron is transferred from substrate to o(2) via the m(ii) center to which they are both bound, thereby obviating the need for an integral change in metal redox state. this model is tested by usin ... | 2008 | 18492808 |
| enantiomer-specific binding of ruthenium(ii) molecular wires by the amine oxidase of arthrobacter globiformis. | the copper amine oxidase from arthrobacter globiformis (agao) is reversibly inhibited by molecular wires comprising a ru(ii) complex head group and an aromatic tail group joined by an alkane linker. the crystal structures of a series of ru(ii)-wire-agao complexes differing with respect to the length of the alkane linker have been determined. all wires lie in the agao active-site channel, with their aromatic tail group in contact with the trihydroxyphenylalanine quinone (tpq) cofactor of the enzy ... | 2008 | 18507382 |
| the shortest wire. | 2008 | 18508968 | |
| analysis of enzyme-treated red blood cell surface and haemagglutination using a theory of soft-particle electrophoresis. | enzymatic treatment of red blood cells is thought to reduce the cell zeta (zeta) potential, effectively decreasing the distance between cells to less than the length of an immunoglobulin g antibody binding site, and resulting in agglutination of cells. however, the zeta potential given by smoluchowski's formula is based on theories of the electrophoresis of hard colloidal particles. a theory has recently been developed for the electrophoresis of colloidal particles covered with polyelectrolytes, ... | 2008 | 18510578 |
| manipulation of sinapine, choline and betaine accumulation in arabidopsis seed: towards improving the nutritional value of the meal and enhancing the seedling performance under environmental stresses in oilseed crops. | sinapoylcholine (sinapine) is the most abundant antinutritional phenolic compound in cruciferous seeds. the quaternary ammonium compounds, choline, betaine and n,n-dimethylglycine, reside along a biosynthetic pathway linked to the synthesis of membrane phospholipids and neurotransmitters with various biological functions. in chicken, choline intake is required for optimal egg-laying performance and a choline supplement in diet is positively correlated with weight gains. a key step in sinapine bi ... | 2008 | 18515127 |
| selection and identification of bacterial strains with methyl-tert-butyl ether, ethyl-tert-butyl ether, and tert-amyl methyl ether degrading capacities. | nine bacterial strains isolated from two hydrocarbon-contaminated soils were selected because of their capacity for growth in culture media amended with 200 mg/l of one of the following gasoline oxygenates: methyl-tert-butyl ether (mtbe), ethyl-tert-butyl ether (etbe), and tert-amyl methyl ether (tame). these strains were identified by amplification of their 16s rrna gene, using fdl and rd1 primers, and were tested for their capacity to grow and biotransform these oxygenates in both mineral and ... | 2008 | 18522454 |
| endohexosaminidase-catalysed glycosylation with oxazoline donors: fine tuning of catalytic efficiency and reversibility. | a complete series of oxazoline di-, tri-, tetra-, and hexasaccharides, corresponding to the core sections of n-linked glycoprotein high mannose glycans, together with the corresponding oligosaccharides containing a central glucose unit, were synthesised and tested as glycosyl donors for glycosylation of a glcnacasn glycosyl amino acid catalysed by the endohexosaminidases m (endo m), a (endo a) and h (endo h). whilst endo h did not catalyse any glycosylation reactions, both endo m and endo a effi ... | 2008 | 18537207 |
| on the role of histidine 351 in the reaction of alcohol oxidation catalyzed by choline oxidase. | choline oxidase catalyzes the four-electron, flavin-linked oxidation of choline to glycine betaine with transient formation of an enzyme-bound aldehyde intermediate. the recent determination of the crystal structure of choline oxidase to a resolution of 1.86 a established the presence of two histidine residues in the active site, which may participate in catalysis. his466 was the subject of a previous study [ghanem, m., and gadda, g. (2005) biochemistry 44, 893-904]. in this study, his351 was re ... | 2008 | 18540638 |
| high benzene concentrations can favour gram-positive bacteria in groundwaters from a contaminated aquifer. | exposure to pollution exerts strong selective pressure on microbial communities, which may affect their potential to adapt to current or future environmental challenges. in this microcosm study, we used dna fingerprinting based on 16s rrna genes to document the impact of high concentrations of benzene on two bacterial communities from a benzene-contaminated aquifer situated below a petrochemical plant (siren, uk). the two groundwaters harboured distinct aerobic benzene-degrading communities able ... | 2008 | 18540887 |
| isolation of alkali-tolerant benzene-degrading bacteria from a contaminated aquifer. | to isolate benzene-degrading strains from neutral and alkaline groundwaters contaminated by benzene, toluene, ethylbenzene, xylenes (btex) from the siren aquifer, uk, and to test their effective ph range and ability to degrade tex. | 2008 | 18544140 |
| production of surfactant by arthrobacter paraffineus atcc 19558. | a. paraffineus atcc 19558 grown in mmsm (modified mineral salts medium) containing hydrocarbon produced surfactant, with a maximum cmc(-1) value obtained by using hexadecane as the carbon source. no activity of surface active agent in whole broth was observed when glucose was used in the mmsm instead of hexadecane. the biomass concentration obtained with glucose was about 40% of that obtained with hexadecane. glucose (4%) in the medium containing hexadecane caused a 27 and 21% decrease of biomas ... | 1982 | 18546108 |
| mode of uptake of insoluble solid substrates by microorganisms. i: sterol uptake by an arthrobacter species. | the mode of uptake of sterols, which are nearly insoluble in water by an arthrobacter species, was studied on the basis of substrate transfer via the aqueous phase (solubilization/pseudosolubilization) and through direct contact with sterol particles. growth of the organism, on stero powder was predominantly in nonlogarithmic in character, indicating a possible limitation of substrate transfer. soluble sterol was shown to be the preferential form of the substrate for assimilation by the organism ... | 1983 | 18548628 |
| thermodynamic analysis of denaturant-induced unfolding of hodc69s protein supports a three-state mechanism. | thermodynamic stability parameters and the equilibrium unfolding mechanism of his 6hodc69s, a mutant of 1 h-3-hydroxy-4-oxoquinaldine 2,4-dioxygenase (hod) having a cys to ser exchange at position 69 and an n-terminal hexahistidine tag (his 6hodc69s), have been derived from isothermal unfolding studies using guanidine hydrochloride (gdnhcl) or urea as denaturants. the conformational changes were monitored by following changes in circular dichroism (cd), fluorescence, and dynamic light scattering ... | 2008 | 18549245 |
| growth and phosphate uptake of a high phosphate accumulating bacterium, arthrobacter globiformis pab-6 in continuous culture. | a high phosphate accumulating bacterium, arthrobacter globiformis pab-6, was grown in a chemostat under glucose-limitation. two different growth patterns at steady state with various dilution rates were obtained. in one case, cells having a coccus shape tended to washout at a low dilution rate, 0.2 (h(-1)). in another, cells with a rod shape grew faster and gave a good steady-state growth at a dilution rate of 0.4. such a close relationship between growth rate and cell morphology was found both ... | 1983 | 18551481 |
| mathematical simulation of pseudo-crystallofermentation of hydrocortisone by arthrobacter simplex. | a mathematical model has been developed to simulate the pseudo-crystallofermentation process of hydrocortisone by arthrobacter simplex. the model describing the process included considerations on the kinetics of microbial growth, the rate of enzyme formation, the rate of substrate dissolution, the rate of solute crystallization, and the kinetics of enzymatic reaction. the system of equations was solved numerically by the runge-kutta-gill method. the good agreement between prediction and experime ... | 1985 | 18553666 |
| pilot-plant production of prednisolone using calcium alginate immobilized arthrobacter simplex. | the maximum conversion of hydrocortisone suspensions at initial substrate concentrations greater than 4 g/l by immobilized arthrobacter simplex in a batch reactor was 80-85%. by feeding hydrocortisone suspensions continuously to either a fed-batch-operated stirred tank reactor or to a continuous-flow airlift loop reactor, at a rate such that the soluble hydrocortisone concentration in the reactor remained ca. 0.05 g/l, 95% conversion of substratewas obtained at final product concentrations excee ... | 1986 | 18561228 |
| coimmobilization of substrate and biocatalyst: a method for bioconversion of poorly soluble substances in water milieu. | coimmobilization of biocatalyst and substrate was studied as a method to increase the conversion rate in systems with substrates of extremely low solubility in water. the system studied was the conversion of hydrocortisone to prednisolone by arthrobacter simplex. as a matrix for coimmobilization, alginate turned out to be superior to agar and agarose. after the reaction was complete, the beads were solubilized, andthe cells recovered for reuse, by centrifugation, whereas the prednisolone was ext ... | 1986 | 18561232 |
| plasmon microscopy and imaging ellipsometry of artrobacter oxydans attached on polymer films. | the attachment of artrobacter oxydans 1,388 on a newly synthesized biodegradable copolymer of poly-(hexanlactam)-co-block-poly-(delta-valerolactone) is investigated by optical, microscopic and biochemical methods. the potentials of surface plasmon microscopy and imaging ellipsometry for detecting microorganisms when al films are used to excite plasmons is assessed by comparing images obtained by these methods with dark field microscopy pictures. the experimental results demonstrate that in this ... | 2008 | 18565743 |
| treatment of chromium(vi) solutions in a pilot-scale bioreactor through a biofilm of arthrobacter viscosus supported on gac. | the aim of this work is to evaluate the applicability of a biofilm to the removal of chromium in solution, at a pilot scale. the effect of the initial concentration of metal on the biosorption behavior of an arthrobacter viscosus biofilm supported on granular activated carbon, in batch and column essays was also analyzed. six isotherm equations have been tested in the present study. the best fit was obtained with the freundlich model. it was observed that as the initial chromium concentration in ... | 2009 | 18565747 |
| activated sludge treatment of synthetic wastewater containing pentachlorophenol. | activated sludge treatment of a pentachlorophenol (pcp)-containing synthetic waste was examined. with a waste containing some sugars, and 40-120 mg/l pcp, laboratory activated sludge required about seven days for acclimation. however, the prior addition of a quasipure culture of pcp-metabolizing arthrobacter resulted in immediate acclimation. even with acclimated sludge, however, the system was upset for two days by a simple step change from 40 to 120 mg/l of pcp. the stability of the system to ... | 1983 | 18574814 |
| kinetic model of hydrocortisone 1-en-dehydrogenation by arthrobacter globiformis. | a kinetic model of the hydrocortisone-to-prednisolone transformation by arthrobacter globiformis is constructed using the experimental data obtained in studies of this process. besides adequately describing experimental data, the model allows one to determine the relation between hydrocortisone oxidation and the level of endogenous substrates in bacterial cells, and the relation between the saturating concentration of hydrocortisone in the enzymic system of bacteria and the content of endogenous ... | 1989 | 18587966 |
| kinetic model for the regulation of redox reaction in steroid transformation by arthrobacter globiformis cells. | a kinetic model of hydrocortisone transformation was developed in studies of the kinetics of biochemical systems. the regulatory bases of the model are the biosynthesis of steroid-transforming enzymes and their activity, the level of endogenous substrates, the respiratory chain activity, and the initial concentrations of reagents. when compared, the experimental data completely coincide with the results of the computer modeling, the coincidence being not only qualitative but also quantitative. i ... | 1989 | 18587967 |
| multi-compound electrophoretic assays for tyramine oxidase with a uv area detector imaging multiple windows on a looped capillary. | active pixel sensor uv area imaging and capacitively coupled contactless conductivity detection have been applied in an electrophoretically mediated microanalysis (emma) assay for substrate specificity of tyramine oxidase (arthrobacter sp.). use of the uv area imaging detector to monitor four windows in a capillary with three loops provided intrinsic self-referencing for all species and identified tyramine and 2-phenethylamine as the only reactive components in a multi-compound mixture. continuo ... | 2008 | 18589431 |
| immobilization of arthrobacter simplex in a thermally reversible hydrogel: effect of temperature cycling on steroid conversion. | arthrobacter simplex cells, which convert the steroid hydrocortisone to prednisolone, have been entrapped in a thermally reversible hydrogel. such hydrogels exhibit a lower critical solution temperature (lcst) wherein the gel shrinks and deswells when it is warmed through its lcst, and then reversibly expands and reswells when it is cooled below the lcst. the immobilized cell-hydrogel system has been thermally cycled between two temperatures, each below the lcst. the upper temperature was select ... | 1990 | 18592505 |
| characterization and validation of a bioluminescent bioreporter for the direct detection of escherichia coli. | a two-component bacteriophage-based bioluminescent reporter system was developed for the detection of escherichia coli in environmental samples. the bioreporter system consists of a luxi integrated lambda bacteriophage and a lux-based bioluminescent reporter cell that responds to the infection event through acyl-homoserine lactone (ahl) mediated quorum sensing and bioluminescent signal stimulation. this work addresses the ability of the bioreporter system to detect and quantify the target pathog ... | 2008 | 18593593 |
| ultrasound-enhanced bioprocess. ii: dehydrogenation of hydrocortisone by arthrobacter simplex. | dehydrogenation of hydrocortisone by agitated suspensions of free and immobilized cells of arthrobacter simplex atcc 6946 was investigated under controlled ultrasonic irradiation at a frequency of 20 kh(z). the microbial conversion was optimized first with respect to mechanical agitation and subsequently with respect to an additionally superimposed sonication. the optimization of ultrasound intensity and its mode of application were established at a level which maintained the structural integrit ... | 1991 | 18597329 |
| effects of solvent molecular toxicity and microenvironment composition on the delta(1) dehydrogenataon activity of arthrobacter simplex cells. | solvent selection tests were carried out for the delta(1) dehydrogenation of 6-alpha-methylhydrocortisone-21-acetate by arthrobacter simplex cells in the presence of organic solvents. solubility limits were determined for substrate and product in dry and water-saturated solvents and solvent mixtures. molecular toxicity levels were estimated by measuring the dehydrogenation activity decay of freely suspended cells incubated in solvent-saturated aqueous media. chloroform and n-decan-1-ol were the ... | 1991 | 18597345 |